(a) Field of the Invention
The present invention relates to a method for performing direct communication between terminals, and a terminal supporting the same.
(b) Description of the Related Art
A method of supporting direct communication between terminals by using resources allocated for cellular communication includes a method of allocating some of resources for cellular communication as resources dedicated for direct communication between terminals within cell coverage, and a method of using resources for cellular communication for both cellular communication and direct communication.
It is assumed that direction communication is established between terminals within the cell coverage of a base station. Moreover, it is assumed that a terminal intending to perform direct communication between terminals is able to know location information of resources used for direct communication between terminals over a control channel of cellular communication.
However, there is a possibility that some or all of the terminals intending to perform direct communication may be located outside the cell coverage of the base station. In this case, a terminal located outside the cell coverage of the base station cannot receive a control channel of the base station. Such a terminal cannot obtain information about the resources used for direct communication between terminals.
In general, direct communication between terminals is performed using some of resources for cellular communication. Hence, a signal from a terminal that performs cellular communication and a signal from a terminal that performs direct communication may co-exist within the cell coverage of the base station. If no synchronization is done between all or some of the terminals performing direct communication and the base station, adjacent channel interference may occur between a cellular communication signal and a direct communication signal. Also, inter-symbol interference and inter-carrier interference may occur at a receiving terminal.